Polymer blends; stretching what we can learn through the combination of experiment and theory

Polymer blends offer mechanical and thermodynamic properties which are both unique and attractive for many industrial applications. Practical use requires blends which are partially or completely miscible and so a theoretical means of predicting such behaviour is desirable. Our recent work in applying the lattice Born–Green–Yvon (BGY) theory to a variety of experimental data, including coexistence curves, neutron scattering intensities, and pressure-volume-temperature surfaces, has allowed us to better understand some of the correlations between the microscopic structure and macroscopic behaviour of several common polymer mixtures. In this paper, we test the predictive capability of lattice BGY theory and the transferability of the predictions which the theory makes. We then look at correlations between the values of the microscopic parameters which characterize the blend and its constituents, and the nature and strength of the interaction(s) between the components in the blend.